Power Supply & Output

[Thomas K]

Ok, so this is something I'm returning to after some time, having faith in new tools..

I ordered the big package almost 1.5 years ago now, and I am pretty satisfied with some very minor exceptions..  things I can deal with...

This is however something I am curious about.

I have a Thermaltake "Dr. Power II" power supply tester.
I also have the PC Doctor tester..

Ussually I use the thermal take, mainly for the way its setup, I leave the PC Doctor one in the box, in a drawer for the most part... no need risking having more then one get damaged right?

Now, comes the question.  After a week, on and off, of a customer calling back saying their computer wasnt working, they'd bring it in, it would work fine for me, they take it home, have problems, phone call...  trouble shoot steps assuming bios battery etc, blah blah blah, he gets it running.. next day, rinse, repeat...  same problems.  Finally I decide, ok bring it in, I will test the power supply..  why I didnt do this first I'm not to sure...  but anyways.

Thermaltake tests the PS fine, except for the SATA CABLES, yes, all of them, rather both of them, they come up fine, except the 3.3V ...

Ok, big red screen and loud beep, with a F under 3.3V ... need a new PS right?  sure., order it in, no problem.. 3 days later its in.. (american long weekend)

I get it in, I figure.. ok just to be safe Im gonna check the power supply again.. the new one.. plug it in, wait, why am I getting an error... on the thing.. new power supply, bad sata's ...

Yank out the PC DOCTOR power supply tester.. I figure ok, gonna double check this..

Same results, both PS seem fine EXCEPT the 3.3V power line..  on the PC Doctor, no green light...

Next step.. google.. its your best friend right?  well, mixed reports say 3.3V may or may not be used.. it allows device makers to skip that part on the circuit board, resulting in cheaper parts...  but that nothing uses 3.3V... like I said, confusing.

Does anyone at PC DOCTOR have a ruling on this?  We are talking about a Acer Aspire AX3990-EB20P (purchased new less then 2 years ago..)

I'm looking for some guidance here, already got a call in to consider a return on this power supply..  however, Im concerned about getting a handle on this spec.. (I've had a couple other PS report as bad/missing this sata 3.3V light, that I've disposed of... assuming it was a 'must have' .. and I hate waste..)

[JoshK_PCD]

Hello Thomas,

After a quick internet search, I discovered that you won't get any reading on a PSU tester if the SATA power cables coming form your PSU don't even have the 3.3V wire which is colored orange by standard. This actually makes sense because over the years, I can recall that I've definitely seen more of the instance where it's missing as opposed to present.   

I did, too, also read something that mentioned that a lot of PSUs don't even have that orange 3.3V cable in the wiring because it isn't always necessary, perhaps to cut cost...but I'm guessing most likely because the industry has figured out a way to bypass its presence or has deemed the 3.3V for SATA unnecessary.

Hope this helps.   


Best,

Josh

[Thomas K]

Yea, I get that..  so whats the point in having the 3.3V spec there..  Im worried that I've been replacing perfectly good power supplies simply cause that 3.3V is coming up a fail..  if its failing, or not present...  something is wrong in my mind...  no one should have to compensate for what the industry says on one hand, and does on the other.. they either should update the spec, make it standard, or not. 

Specially when I have new computers (less then 2 years old) come in and are behaving like they, or their components are not getting sufficient power...  which is what more then a few have done..  Not to mention a power supply or two of my own.

[Kris_PCD]

Hi Thomas,

I am sorry to make you wait so long for a response. First let me say that when testing a system that you think might be having power issues, I always recommend starting with a known good power supply of your own. I used to always keep a spare 500w 80 PLUS (usually Silver) PSU that would only be used when testing a system that was showing power issues.

Regarding your actual questions, as far as I am aware there is no easy way to confirm if a power supply uses the 3.3V rail properly right out of the box. In my personal experience, you will be more likely to see a higher end PSU (Starting around $80) use the 3.3V rail correctly, but again that isn't a certainty.

There are only two methods I can think of using to check that may give you some certainty:
   1. Test each and every power supply that passes through your shop, and make a database of their specifications.
   2. Contact the manufacturer of each PSU that you aren't sure about.

Obviously each has more than a few problems of their own, but sadly I can think of no better ways. I am sorry that this answer is so nebulous, and I can only hope that either the industry decides to follow it's own standards, or someone spends the time and money to properly document items of this nature.

Please let me know if you have any other questions.

Thanks,
Kris Templin

[Thomas K]

Kris,

I appreciate that you got back to me at all.  I really wasnt much expecting more help on the matter.. the problem is this..

While the power tester indicated a bad SATA line, the fact that the single wire was missing, was lost on me, I've replaced at least a half dozen power supplies in the last year on the premise.  If they where good, I feel rotten...

This is the thing tho.  Some of these units where not the standard power supply.  Think slimline type power supplies, the ones that run from front to back.. its hard to keep a variety of those in stock, in a small shop like mine, and still get valid results.

The UPSIDE, is the customer has not called me back, and he's never afraid to do so.. but he was also frustrated to the point I wouldn't be surprised if I found out that he had thrown it out the window...

Other behaviours, indicated that should have been the issue... I just wish ... well, you know, repeating myself again.  If that line was being used, it might have been more decisive..